Unveiling the Invisible: Inferior STEMI With an Absent Right Coronary Artery Rescued by PCI to the Left Circumflex Artery.

Coronary artery anomalies, though uncommon, can pose significant diagnostic and therapeutic challenges, especially during acute coronary syndromes (ACS). We present a rare case of a 57-year-old male who presented with classical symptoms of inferior ST-segment elevation myocardial infarction (STEMI). Initial coronary angiography failed to identify the right coronary artery (RCA), eventually revealing an absent RCA ostium. The superdominant left circumflex artery (LCX) was found to be entirely occluded, supplying the territory typically serviced by the absent RCA. Successful primary percutaneous coronary intervention (PCI) was performed using a drug-eluting stent (DES), restoring TIMI-III flow and resolving symptoms promptly. Further imaging with contrast-enhanced computed tomography coronary angiography (CTCA) confirmed the congenital absence of the RCA, emphasising the critical role of advanced imaging in diagnosing coronary anomalies. Our case underscores the importance of considering rare congenital anomalies in acute cardiac presentations. It highlights the pivotal role of rapid recognition, targeted imaging and intervention in such anomalies to ensure optimal patient outcomes. It advocates a multidisciplinary approach, integrating cardiologists, radiologists and interventional specialists to enhance clinical decision-making and management effectiveness in similar complex scenarios.